68018e4c3e test: Avoid excessive locking of `cs_wallet` (Hennadii Stepanov)
7986faf2e0 test: Fix segfault in the psbt_wallet_tests/psbt_updater_test (Hennadii Stepanov)
Pull request description:
The dcd6eeb64a commit (bitcoin/bitcoin#23288) introduced an intermittent failure in the `psbt_wallet_tests/psbt_updater_test` unit test. See bitcoin/bitcoin#23368.
The test failure can be easily made reproducible with the following patch:
```diff
--- a/src/scheduler.cpp
+++ b/src/scheduler.cpp
@@ -57,6 +57,8 @@ void CScheduler::serviceQueue()
Function f = taskQueue.begin()->second;
taskQueue.erase(taskQueue.begin());
+ UninterruptibleSleep(100ms);
+
{
// Unlock before calling f, so it can reschedule itself or another task
// without deadlocking:
```
This PR implements an idea which was mentioned in the [comment](https://github.com/bitcoin/bitcoin/issues/23368#issuecomment-953796339):
> Yes, as I said before this looks like a race where the wallet is deleted before stopping the scheduler: [#23368 (comment)](https://github.com/bitcoin/bitcoin/issues/23368#issuecomment-952808824)
>
> IIRC, the order should be:
>
> * stop scheduler
>
> * delete wallet
>
> * delete scheduler
The second commit introduces a refactoring with no behavior change.
Fixesbitcoin/bitcoin#23368.
ACKs for top commit:
mjdietzx:
Code review ACK 68018e4c3e
Tree-SHA512: d9103f6252aab807453628159dec243bc543a2595eecaa04ec761dca3c2370085592c55d6f50967d69a4ac6e8b5827eec30dd9b025132c99b0bb9aa5911ad915